The present invention relates to motor graders and in particular, relates to a bearing slide arrangement for a motor grader blade.
The grading blade of a motor grader is subject to a host of adjustments and the nature of the mechanism and the nature of the application subjects the system to high loads. In addition, the operating conditions of the motor grader often cause material contamination and which is a particular problem for the slide mechanism of a grader blade as accelerated wear can occur.
Motor grader blades all typically include a slide adjustment for varying the position of the blade beneath the motor grader. Slide rails are provided on the rear surface of the grader blade and slide bearings are provided which engage the rails and allow the rail to slide therebetween.
A motor grader has many applications from rough grading, banking and snow plowing, to fine grading where it is desired to maintain precise grading tolerances. For rough grading applications, it is not critical if there is some excessive play due to wear between the slide rails and the bearings, however, this becomes more critical for precise applications. Most arrangements allow for some adjustment to reduce the tolerance between the bearings and the rails. Typically these systems use a number of large bolts and shims, however, the adjustment thereof is not convenient and requires specialized personnel and tools which are not normally available to the operator.
The present invention provides an alternate structure and method for supporting a motor grader blade which is easier to maintain.
A motor grader blade support arrangement comprises a blade grader with upper and lower slide rails attached to a rear surface of the blade and a blade support structure having a series of upper and lower bearing arrangements which engage the rails and accommodate longitudinal sliding movement of the blade and the slide rails. Each bearing arrangement includes a bearing support holder attached to the support structure with this bearing support holder supporting and retaining a slide bearing. At least some of the bearing arrangements include an adjustment mechanism to reduce tolerances between the slide bearings and the slide rails. The adjustment mechanism includes at least one short stroke hydraulic cylinder supported in the respective bearing holder and acting as an intermediary between the bearing holder and the slide bearing. Each hydraulic cylinder includes a grease fitting and the position of the hydraulic cylinder is adjusted using the grease fitting.
According to an aspect of the invention, the motor grader blade support arrangement has two hydraulic cylinders as part of each adjustment mechanism with these hydraulic cylinders being spaced in the length of the respective slide bearing.
In a further aspect of the invention, each bearing support holder having said adjustment mechanism includes an accessible port for each hydraulic cylinder and the grease fitting is located within the accessible port.
In yet a further aspect of the invention, the series of upper and lower bearing arrangements include at least two lower bearing arrangements, each having said adjustment mechanism and at least two upper bearing arrangements, each having said adjustment mechanism.
The present invention is also directed to a bearing support arrangement for a slide rail of a motor grader blade. The bearing support arrangement comprises a bearing holder, a removable bearing received in the bearing holder, and at least one adjustment mechanism controlling the position of the bearing in the holder. The adjustment mechanism is received in the holder and acts on a rear face of the bearing to space the rear face of the bearing from the holder as a function of the adjustment mechanism. The adjustment mechanism includes at least one short stroke hydraulic cylinder which is normally sealed with a fixed volume of fluid. The at least one hydraulic cylinder includes a fitting for varying the fixed volume of the fluid as required to compensate for bearing wear.
In yet a further aspect of the invention, the bearing support arrangement has a bearing holder which has a U-shaped channel in which the removable bearing is received.
In yet a further aspect of the invention, the adjustment mechanism includes two short stroke hydraulic cylinders spaced in the length of the bearing holder.
In yet a further aspect of the invention, the bearing on a rear surface thereof, has a recessed area which partially receives the hydraulic cylinders.